The proposed investigations represent continuation of a long term project on diverse aspects of the biochemistry of the mammalian male genital tract. Special emphasis is given to the mechanisms and control of molecular events related to the development and functions of male accessory glands of reproduction and the testis. Additional studies will be carried out on the structure and properties of three unique forms of transglutaminase that were recently found in the anterior prostate (coagulating) gland and its secretion. The ability of these and other forms of transglutaminase to catalyze incorporation of natural polyamines into these enzymes and other proteins will be further investigated, particularly as regards the possible functional significance of these reactions. A flavoprotein from seminal vesicle that rapidly oxidizes a variety of low molecular weight sulfhydryl compounds, and which was recently found in joint work between this and another laboratory, will be scrutinized further from both mechanistic and physiological standpoints. More work will be done on the turnover of ornithine decarboxylase in relation to the rapid formation and secretion of spermidine and spermine in rat ventral prostate, especially with respect to a very active macromolecular ornithine decarboxylase inactivating factor in this tissue. It is also intended to explore extensively the metabolism and functions of 5'-methylthioadenosine and its metabolic degradation products in prostate and other tissues, vis-a-vis this thionucleoside being a major b-product of polyamine biosynthesis.